The present invention relates to a reproduction apparatus for a signal recorded on a medium such as an optical storage medium, and in particular to a technique making it possible to protect a copyright of the signal recorded on the medium.
A digital video disk (DVD) for recording an audio/video (AV) signal compressed by using MPEG2 has a problem that the AV signal could be copied without quality degradation because the AV signal is handled as digital data.
In opposition to this, there has been introduced a technique of an electronic watermark for superimposing information such as permission, inhibition, or permission of only one generation as to copying so that the user may not sense it as described in Nikkei Electronics, Feb. 24, 1997, pp. 99-123. In the above described technique, there is described, for example, a method for conducting copying prevention processing on analog output in accordance with a detected signal.
In the case of a medium such as a broadcasting which permits copying only once, however, it is not considered to protect a copyright by restricting reproduction, using a player of each user, of a pirated edition disk which is produced by copying a signal onto a DVD-R disk (capable of recording the signal once) or the like and thereafter further copying the signal from the DVD-R disk to a DVD-ROM.